let toString = {
  numToString: (str) => {
    str = str + '';
    var len = str.length - 1;
    var idxs = [
      '',
      '十',
      '百',
      '千',
      '万',
      '十',
      '百',
      '千',
      '亿',
      '十',
      '百',
      '千',
      '万',
      '十',
      '百',
      '千',
      '亿',
    ];
    var num = ['零', '一', '二', '三', '四', '五', '六', '七', '八', '九'];
    return str.replace(/([1-9]|0+)/g, function ($, $1, idx, full) {
      var pos = 0;
      if ($1[0] != '0') {
        pos = len - idx;
        if (idx == 0 && $1[0] == 1 && idxs[len - idx] == '十') {
          return idxs[len - idx];
        }
        return num[$1[0]] + idxs[len - idx];
      } else {
        var left = len - idx;
        var right = len - idx + $1.length;
        if (Math.floor(right / 4) - Math.floor(left / 4) > 0) {
          pos = left - (left % 4);
        }
        if (pos) {
          return idxs[pos] + num[$1[0]];
        } else if (idx + $1.length >= len) {
          return '';
        } else {
          return num[$1[0]];
        }
      }
    });
  },
};
export default toString;
